1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 #ifndef _DRIVERS_VIRTIO_VIRTIO_PCI_COMMON_H 3 #define _DRIVERS_VIRTIO_VIRTIO_PCI_COMMON_H 4 /* 5 * Virtio PCI driver - APIs for common functionality for all device versions 6 * 7 * This module allows virtio devices to be used over a virtual PCI device. 8 * This can be used with QEMU based VMMs like KVM or Xen. 9 * 10 * Copyright IBM Corp. 2007 11 * Copyright Red Hat, Inc. 2014 12 * 13 * Authors: 14 * Anthony Liguori <aliguori@us.ibm.com> 15 * Rusty Russell <rusty@rustcorp.com.au> 16 * Michael S. Tsirkin <mst@redhat.com> 17 */ 18 19 #include <linux/module.h> 20 #include <linux/list.h> 21 #include <linux/pci.h> 22 #include <linux/slab.h> 23 #include <linux/interrupt.h> 24 #include <linux/virtio.h> 25 #include <linux/virtio_config.h> 26 #include <linux/virtio_ring.h> 27 #include <linux/virtio_pci.h> 28 #include <linux/virtio_pci_legacy.h> 29 #include <linux/virtio_pci_modern.h> 30 #include <linux/highmem.h> 31 #include <linux/spinlock.h> 32 33 struct virtio_pci_vq_info { 34 /* the actual virtqueue */ 35 struct virtqueue *vq; 36 37 /* the list node for the virtqueues list */ 38 struct list_head node; 39 40 /* MSI-X vector (or none) */ 41 unsigned msix_vector; 42 }; 43 44 /* Our device structure */ 45 struct virtio_pci_device { 46 struct virtio_device vdev; 47 struct pci_dev *pci_dev; 48 struct virtio_pci_legacy_device ldev; 49 struct virtio_pci_modern_device mdev; 50 51 bool is_legacy; 52 53 /* Where to read and clear interrupt */ 54 u8 __iomem *isr; 55 56 /* a list of queues so we can dispatch IRQs */ 57 spinlock_t lock; 58 struct list_head virtqueues; 59 60 /* array of all queues for house-keeping */ 61 struct virtio_pci_vq_info **vqs; 62 63 /* MSI-X support */ 64 int msix_enabled; 65 int intx_enabled; 66 cpumask_var_t *msix_affinity_masks; 67 /* Name strings for interrupts. This size should be enough, 68 * and I'm too lazy to allocate each name separately. */ 69 char (*msix_names)[256]; 70 /* Number of available vectors */ 71 unsigned msix_vectors; 72 /* Vectors allocated, excluding per-vq vectors if any */ 73 unsigned msix_used_vectors; 74 75 /* Whether we have vector per vq */ 76 bool per_vq_vectors; 77 78 struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev, 79 struct virtio_pci_vq_info *info, 80 unsigned idx, 81 void (*callback)(struct virtqueue *vq), 82 const char *name, 83 bool ctx, 84 u16 msix_vec); 85 void (*del_vq)(struct virtio_pci_vq_info *info); 86 87 u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector); 88 }; 89 90 /* Constants for MSI-X */ 91 /* Use first vector for configuration changes, second and the rest for 92 * virtqueues Thus, we need at least 2 vectors for MSI. */ 93 enum { 94 VP_MSIX_CONFIG_VECTOR = 0, 95 VP_MSIX_VQ_VECTOR = 1, 96 }; 97 98 /* Convert a generic virtio device to our structure */ 99 static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev) 100 { 101 return container_of(vdev, struct virtio_pci_device, vdev); 102 } 103 104 /* wait for pending irq handlers */ 105 void vp_synchronize_vectors(struct virtio_device *vdev); 106 /* the notify function used when creating a virt queue */ 107 bool vp_notify(struct virtqueue *vq); 108 /* the config->del_vqs() implementation */ 109 void vp_del_vqs(struct virtio_device *vdev); 110 /* the config->find_vqs() implementation */ 111 int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs, 112 struct virtqueue *vqs[], vq_callback_t *callbacks[], 113 const char * const names[], const bool *ctx, 114 struct irq_affinity *desc); 115 const char *vp_bus_name(struct virtio_device *vdev); 116 117 /* Setup the affinity for a virtqueue: 118 * - force the affinity for per vq vector 119 * - OR over all affinities for shared MSI 120 * - ignore the affinity request if we're using INTX 121 */ 122 int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask); 123 124 const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index); 125 126 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY) 127 int virtio_pci_legacy_probe(struct virtio_pci_device *); 128 void virtio_pci_legacy_remove(struct virtio_pci_device *); 129 #else 130 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev) 131 { 132 return -ENODEV; 133 } 134 static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev) 135 { 136 } 137 #endif 138 int virtio_pci_modern_probe(struct virtio_pci_device *); 139 void virtio_pci_modern_remove(struct virtio_pci_device *); 140 141 #endif 142